1. Field of the Invention
The present invention relates to a safety ski binding, preferably adapted to hold the front of a boot onto a ski.
2. Description of Background and Other Information
Safety ski bindings, specifically front abutments of the aforementioned type generally comprise a body fixed to the ski which supports, in a rear part, a movable jaw which is either of monoblock construction or comprises two independent lateral retention wings which are journalled, respectively, on the binding body by means of individual axes.
The binding body of a front abutment of the type mentioned is typically constituted by two parts nested in one another at the front, namely, a lower part or base which is affixed to the ski and an upper movable part which supports the jaw. The body likewise contains a mechanism for energization of the jaw, which is constituted by an energization spring and a force transmission device. The upper part of the body which supports the jaw is vertically upwardly movable during a rear fall which can cause, by means of a rear fall compensation device known per se, a lessening of the lateral release, i.e., a lowering of the lateral force threshold, exerted by the boot on one of the lateral retention wings, from which the binding releases. The upward movement of the upper part of the body can ultimately lead to the release of the boot when the upward angular clearance of the upper part of the body is sufficient. In front abutments of this type, the journalling between the upper part of the body, which is vertically movable, and the lower base affixed to the ski is achieved by means of a transverse horizontal journal axle which extends completely through these two elements, or even two transverse and coaxial half-axles which establish the linkage between the lateral adjacent surfaces of the upper part of the body and those of the base, respectively.
A front abutment of this type is described for example, in German Patent No. 3,612,697. In such a front abutment, the journal axle of the upper part of the body on the base has a relatively small diameter, whereas the forces that this axle transmit are relatively great. These forces are due to the thrust of the rear binding to which are added those which are due to the flexion of the ski, during skiing, the sum of these forces being able to reach 200 daN [decaNewton]. As a result, an axle of small diameter generates between its exterior surface and the surface of its support greatly elevated contact pressures which create a rapid wear-and-tear leading, in turn, to a certain amount of play and an inferior functioning of the binding. In addition, there can result a distortion of the axle or even a defect in alignment of the two opposed transverse half-axles, which is due to the elevated stresses during use of the binding.